Chemical-equilibrium model of impurity incorporation inn-typea-Si:H

Abstract
A chemical-equilibrium model for plasma-enhanced chemical vapor deposition of a-Si:H is developed to interpret the irregular incorporation of As and P. The model shows that the irregularity occurs only for nondoping impurities; their distribution coefficient is inversely proportional to the rf plasma power, which leads to the large As concentration enhancement observed under low-power growth conditions. A configuration-energy diagram is proposed to account for this enhancement based on the preferential formation of stable, inactive As in a configuration other than the usual interconverting three- and fourfold-coordinated sites.